Coring device



Oct- 25, 1965 c. E. BANNISTER 3,280,922

CORING DEVICE 5 Sheets-Sheet l Original Filed May 24, 1963 INVENTOR.

A TTOA/Y Oct. 25, 1966 CORING DEVICE Original Filed May 24, 1965 C. E. BANNISTER 5 Sheets-Sheet 2 Oct. 25, 1966 C,

Original Filed May 24, 1963 E. BANNISTER CORING DEVICE 5 Sheets-Sheet 5 C/yc/e E Bann /Jer INVENTOR.

United States Patent O 3,280,922 CGRING DEVICE Clyde E. Bannister, 2727 Carolina Way, Houston, Tex. Griginal application May 24, 1963, Ser. No. 283,023, now Patent No. 3,227,228, dated Jan. 4, 1966. Divided and this application June 2, 1965, Ser. No. 470,289 6 Claims. (Cl. 175-4) This invention pertains to the improvement of subsurface drilling techniques and more especially to novel apparatus for sampling the formation (frequently called coring) in a borehole drilled with a rotary rig.

This application is a division of application Serial No. 283,023, iiled May 24, 1963, for Rotary Drilling and Bohehole Coring Apparatus and Method, now U.S. Patent 3,227,228, issued January 4, 1966.

The prior art techniques are well known and w1ll be considered just briey to point up the unusual signicance of the invention.

It is conventional practice in certain localities to sample a formation at different levels in a borehole to ascertain the proximity of an oil bearing formation. The borehole is drilled by a rotary rig, a term used herein. to describe a drill assembly having a drill string comprismg drill pipe, drill collars, a bit, and apparatus for rotating the drill string in one direction during the drilling operation. Drill mud is pumped through the drill string and circulated upwards, around the drill string, to wash out cuttings, and is maintained at a relatively heavy weight to prevent borehole cave-ins. When samples of the formation are desired the drill string is removed and a sidewall sampling tool is lowered on a cable.

In another arrangement the drill string has a special bit that drills and can be used to take cores by proper manipulation of a wire line dropped down the center of the drill string. The mud circulation is stopped and the kelly is removed to gain access to the drill pipe central passage. Obviously, the selection of cutting bits is limited if core samples have to be taken in this manner and cores can only be taken from the bottom of the bore hole.

My invention includes a coring device having general utility which is an improvement over the device described and claimed in my United States Patent 2,717,760. The sample-taking projectile will shoot-back, i.e., return to the barrel or'casing, irrespective of how far the projectile enters the formation, making the coring device useful in all types of formations.

The improvement of my coring device includes in one embodiment the arrangement of the second explosive means the one that provides positive shoot-back) on the sample-taking projectile and the provision of means on the projectile to fire the second explosive means at a predetermined time after the explosive means lires.

A description of my invention commences herewith, reference being made to the attached drawings, wherein,

FIG. 1 is a horizontal section of one form of my improved coring device and illustrating the arrangement of parts in the normal, ring position.

FIG. 2 is an enlarged view of the locking means on the rea-ction member shown in FIG. l.

FIG. 3 is a horizontal section of the coring device illustrated in FIG. l, taken along the same section lines, with the parts shown in the position after coring and before shoot-back.

FIG. 4 is a horizontal section, `as FIGS. 1 and 3 with the coring device parts shown in their position after shoot-back.

FIG. 5 is a horizontal section of another coring device suitable for use in a coring collar, illustrating the arrangement of parts before firing of any explosive.

FIG. 6 is a horizontal section of the same coring device ICC as illustrated in FIG. 5, showing the arrangement of parts during ejection of the plug.

FIG. 7 is an enlarged view of the check valve shown in FIGS. 5 and 6.

It is apparent to one skilled in the art that the mechanical apparatus can take several forms and still carry out the desired function.

One embodiment of my improved coring device, illustrated in FIGS. 1 through 7, has the advantage of positive shoot-back of the sample-taking projectile. When used with the aforementioned coring collar 20 the cores are retrieved and conveniently stored until the drill string is removed.

In my prior form of coring device, described in United States Patent 2,717,760, a second explosive mounted in the barrel or casing at the opposite end from the first eX- plosive shoots the sample-taking projectile back. The tiring of the second explosive is dependent on the sampletaking projectile moving at least a given distance into the formation to ignite a powder train housed in the casing. In especially hard formations the projectile may not have a su'icient distance, even though an adequate sample is taken, to fire the second explosive. And, even if the projectile moves far enough to just re the second explosive, a large chamber volume is present, shoot-back force on the projectile.

In accordance with my improved coring device, the second explosive means :and means for firing same at a predetermined time after the rst explosive fires are carried by the sample-taking projectile. No matter how far i the projectile moves the second explosive is fired and exerts a substantial shoot-back force.

With specic reference to FIG. l, one embodiment of my improved coring device 21 is mounted in coring collar 20 disposed in borehole 150. The coring device casing 151 is annular, having one end 152 that firmly seats in an inside wall recess 155 of coring collar 20 and an opposite end 156 threaded to engage with mating threads 153 in the wall of coring collar aperture 154, thereby providing easy access for removal of the coring device 21. The coring device casing 151 is constructed of Ia heavy metal and of suicient size to prevent expansion dueto the explosions therein.

Disposed within coring device casing 151 is the sampletaking projectile 160 having cylindrical head 161 and `a narrower cylindrical body 162 extending axially through and supported by an lannular plug 163 threaded into the opening at lcasing end 152. A suitable seal, such as O-ring 164, between the body 162 and plug 163 prevents drill mud 6 from entering. Samples are taken by 'the hollow end 165 of body 162, which is closed by a plug 166 to prevent drill mud 6 from entering but suiiiciently flexible to bend inwardly and to be forced into the projectile hollow with the formation sample (see FIG. 4), as lair or fluid therein escapes through ports 167. Air or uid can pass only out from the hollow of body 162 through ports 167 due to check valves 250 composed of .a at spring 253 attached at one end in a recess 252 by fastener 254. Coring collar 20 has an aperture that receives the body end 165 and allows movement into Ia formation. Movement of projectile head 161 past the check valves 210 is prohibited by a lock ring 211 retained in a slot in the inner casing wall just adjacent the check valves 2,10 and after lip 191.

The projectile 160 is propelled into the formation `by l a packaged charge of explosive 170 disposed in the closed casing end 156 adjacent head 161, the explosive 170 being fired by an electric detonator 171 activated with a current received over cable 172 recess mounted in the outer wall of coring lcollar 20. Air or iiuid forward of the head t 161 escapes through check valves 210 in ports 183 at the Y diminishing the initiall casing end 152 that allow fluid to ow out but not into casing 151.

The check valves 210 can be of several conventional constructions. FIGS. 1 and 7 illustrate the details of one form of suitable check valve and the other Figs. show the check valves 210 in schematic form.

Fluid from Within casing 151 moves -a pop valve member 216 Vaway from a seat 217 threaded in part 183. The valve member 216 is supported in a spider 218 threaded in part 183 and having ports 219 for the uid to pass through. A closing force provided by a helical spring 215 holds valve member 216 against seat 217 to prevent fluid from outside casing 151 from passing into casing 151.

When explosive 170 is fired, vent ports 173 in casing end 156 are closed by Ian annular sleeve 174 axially disposed within casing 151 about projectile 160, as shown in FIG. 1, and a tight gas seal is provided by suitable means, such as O-ring 175 in the outer circumference of head 161. The aforementioned parts in coring device 21 take the position shown in FIG. 3 lafter the explosive 17 0 is fired.

The projectile 160 carries an annular packed charge of explosive 177 immediately adjacent the opposite side of head 161 from explosive 170, which is fired by a delay fuse 178, such as an impregnated cloth or black powder train, being ignited Iat one end by the explosion of explosive 170 and firing explosive 177 at a predetermined time later.

The projectile 160 also carries an annular reaction member 180 that moves with projectile 160 in the forward direction but is slidable on body 162 and relative to sleeve 174, with a gas seal provided by O-rings 181, to allow the reaction member 180 to move separately relative to sleeve 174 and projectile 160 after explosive 177 is fired.

Reaction member 180 includes a locking means 184 composed of separate pins 189 that slide freely in radial passages 187 (see FIG. 2) opening to sleeve 174 and having tapered heads 185 (see FIG. 2) that can engage in circumferential slots 186 in the inner wall of sleeve 174. As shown only in FIG. 2, the passages 187 have tooth- -shaped walls 195 arranged to permit free radial outward movement of a pin attached exible Washer 188 but to prevent rearward movement, thereby firmly locking the pins 189 to sleeve 174.

After the predetermined time delay controlled by delay fuse 178, the projectile 160 will be in some forward position, such as shown in FIG. 3, the explosive 177 lires and forces reaction member 180 towards casing end 152. Explosion gases enter ythrough separate ports 190 to act on the rear of each of pins 189, forcing them radially outward, and very quickly lodging them firmly in one of sleeve slots 186. Then sleeve 174 moves a small distance towards casing end 152 to engage a lip 191 in the inner Wall of casing 151, ali-gning sleeve ports 196 with vent ports 173 at casing end 156, permitting the .gases from the explosion to escape. The reaction member 180 cannot move further in the direction of casing end 152 .and the explosive gases force projectile head 161 rearward, towards casing end 156, withdrawing the projectile body 162 from the formation.

FIG. 4 illustrates the position of the coring device parts after the projectile with the core therein has been retrieved.

Another embodiment of my improved corin-g device is shown in FIGS. 5, 6, and 7. In this arrangement the number of parts is reduced and the gases from the first explosive are exhausted from a port, irrespective of how far the projectile moves, by opening the port at a predetermined time after the explosion of the first explosive.

Several of the parts are the same as in the embodiment shown in FIGS. 1 through 4 and bear the same reference numerals.

The sleeve 174 is eliminated and the projectile 160 fits slidably Within the casing 151. O-ring 175 sealing the head 161 against the inner casing Wall. The projectile 160 carries the explosive 171 and locking means 184 as described previously in detail, 'the slots 186 being in the inner Wall of casing 151.

Gases are vented fro-m within casing 1-51 through oneway check valves 20'0 during the forward movement of projectile 160. The -gases from the explosion of explosive 170 are exhausted by blowing tout a conical frust-rurn shaped metal plug 201 disposed in tapered port 205 in casing end 156 with the larger diameter side facing Within casing 151. The plug 201 is surrounded by Ia packaged ring of explosive 202 disposed in a circumferential groove 215 and connected to one end of delay fuse 203. The opposite end of delay fuse 203 connects with explosive 170 and is ignited at the same time. Plug 201 has an eccentric outer lip 204 that causes plug 201 to travel lout of alignment with the port 205, reducing the possibility that the plug 201 will be reinserted as t-he projectile moves rearward during shoot-back.

The `time relation of the explosions is controlled by the delay fuses 178 and 203. The explosive 170 fires and ignites one end of delay fuses 178 and 203. After a predetermined time period the explosive 202 lires, ejecting plug 201. The projectile 160 may have completed taking a sample by that time. Next, the explosive 171 fires, shooting the projectile 160 back, .as the gases from explosive escapes out of port 205. Thus, the time delay of fuse 203 is shorter than fuse 178.

The locking means 184 functions as described previously, `the only difference being 'that the slots 184 are in casing 151 and pins 189 lock reaction member 180 Iand casing 151 together.

The disclosed embodiments of my invention are presented merely as examples of suitable apparatuses and methods. Changes, modifications and other embodiments arrange in accordance with the teaching .of my invention are part of my claimed invention as defined in 'the appended claims.

What is claimed is:

1. Apparatus for formation sampling, comprising:

a captive projectile having a head and a hollow opposite end for receiving a sample,

a first explosive means adjacent said head to impel .said projectile in one direction to take Ia sample,

"a second explosive Imeans carried by said projectile for creating a force to .impel said projectile in the opposite direction and retrieve the sample,

means carried by said projectile for firing said second explosive means at a predetermined time after said first explosive means fires.

2. Apparatus as described in claim 19, wherein;

said head has first and second opposite sides,

said first explosive means `acts on said first head side and said second explosive means acts on said second head side,

said projectile carries a reaction member means disposed on the opposite side of said second explosive means from said head to provide a gas escape barrier, said member means locking in place after said second explosive means is fired to permit relative movement of said projectile in said opposite direction.

3. Apparatus for formation sampling, comprising:

a casing,

a captive projectile slidably mounted in said casing and having a head at one end and a hollow opposite end f-or taking a sample,

a first explosive disposed `adjacent said head to impel said projectile partly from said Casin-g,

a sleeve -disposed between and slidable with respect to said casing and said projectile,

a first vent port in said casing adjacent said projectile opposite end,

a second vent port adjacent said projectile head,

said sleeve closing said second vent port when said projectile is `in the position to be fired and opening said second vent port when said sleeve is moved toward the opposite end of said casing to a second position,

said casing having a stop means to prevent further movement Iof said sleeve at said sleeve second position,

a member slidable on said projectile adjacent said head and arranged to effectively seal off a chamber formed by said sleeve, projectile, head and member,

a second explosive disposed in said chamber,

a time delay fuse disposed in said head connecting said first and second explosives,

said member having locking means operated by gases from the explosion of said second explosive to connect said member and sleeve together, car-rying said sleeve to .said second position to open said second port after said second explosive has fired, and thereby retrieving said projectile into said casing.

4. Apparatus for formation sampling, comprising:

a casing,

a Vcap-tive projectile slidably mounted `in said casing and having a head at one end and a hollow opposite end for rtaking a sample,

said casing having a closed end at said head end of said propectile to form a sealed chamber between said -head and closed casing end,

a first explosive means :disposed in said chamber,

a port in said casing closed end to permit escape of gases from the explosion of said first explosive,

means closing said port to prevent gases from escaping `during the explosion of said first explosive means,

means for opening said port at a predetermined time after said first explosive fires,

a second explosive means carried by said projectile for creating a force to impel said projectile in the opposite direction and retrieve the sample,

means carried by said projectile for firing said second explosive means at a predetermined time after said first explosive means fires and after said port is opened.

5. Apparatus as described in claim 4, wherein:

said port closing means is a removable plug,

said port opening means includes an explosive means arranged to remove said plug `and fired by a delay fuse located in said casing that is ignited -by the explosion of said rst explosive means,

said ring means for said secon-d projectile ais a delay fuse located in sai-d projectile and ignited by the explosion of said first explosive means.

6. Apparatus as described in claim 4, wherein:

said plug has a substantially conical vfrustrunr shape and is disposed with the larger diameter end facing the interior of said casing,

said port opening means removes said plug by igniting a charge of explosive disposed circumferentially ab out said plug in said port,

said delay fuses are trains of relatively slow burning powder rthat extend to said chamber to ignite by said first explosive means and terminate at the respective explosives,

said powder train for said second explosive means being longer t-han the powder t-rain for said plug removing explosive.

References Cited by the Examiner UNITED STATES PATENTS 10/1957 Laual 175-4 10/1957 Laual 175-4 35 J. A. LEPPINK, Assistant Examiner. 

1. APPARATUS FOR FORMATION SAMPLING, COMPRISING: A CAPTIVE PROJECTILE HAVING A HEAD AND A HOLLOW OPPOSITE END FOR RECEIVING A SAMPLE, A FIRST EXPLOSIVE MEANS ADJACENT SAID HEAD TO IMPEL SAID PROJECTILE IN ONE DIRECTION TO TAKE A SAMPLE, A SECOND EXPLOSIVE MEANS CARRIED BY SAID PROJECTILE FOR CREATING A FORCE TO IMPEL SAID PROJECTILE IN THE OPPOSITE DIRECTION AND RETRIEVE THE SAMPLE, 